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A bioplastic is a type of plastic that can be made from plant starches or gelatins/agars. They are better for the environment because they are not derived from petroleum. They can also be easily made at home with a few simple ingredients and a stove!

Steps

Method1

Using Cornstarch and Vinegar

1

Gather the necessary materials. To make this type of bioplastic, you will need cornstarch, distilled water, glycerol, white vinegar, a stove, a saucepan, a silicone spatula, and food coloring (if desired). These items should be readily available at the grocery store or online. Glycerol is also called glycerine, so try searching for that if you’re having trouble finding glycerol. The following amounts of each ingredient are needed to make the bioplastic:

10ml distilled water

0.5-1.5g glycerol

1.5g cornstarch

1ml of white vinegar

1-2 drops food coloring

Adult supervision is recommended.

2

Combine all of the ingredients and stir together. Add all of the ingredients to the saucepan and stir to combine with the spatula. Stir until you get rid of most of the lumps in the mixture. At this stage, the mixture will be a milky white color and quite watery.

If you add the wrong amounts of ingredients, just dispose of the mixture and start again.

3

Heat on medium-low. Place the saucepan on the stove and set the heat to medium-low. Stir continuously as the mixture heats. Bring it to a gentle boil. As the mixture heats, it will become more translucent and begin to thicken.

Remove the mixture from the heat when it becomes clear and thick.

Total heating time will be around 10-15 minutes.

Lumps may begin to form if the mixture gets overheated.

Add one-two drops of food coloring at this stage, if you would like to color the plastic.

4

Pour the mixture onto foil or parchment paper. Spread the heated mixture onto a piece of foil or parchment paper to let it cool. If you would like to mold the plastic into a shape, it must be done while it is still warm. See the last method for details on molding the plastic.

Remove any bubbles that you see by poking them with a toothpick.

5

Allow the plastic to dry for at least two days. It will take time for the plastic to dry and harden. As it cools, it will begin to dry out. Depending on the thickness of the plastic, it can take longer for it to dry. If you make one small thick piece it will take longer to dry than a thinner larger piece.

Leave the plastic in a cool, dry place for this process.

Check the plastic after two days to see if it has fully hardened.

Method2

Using Gelatin or Agar

1

Gather the necessary materials. To make this type of bioplastic, you will need gelatin or agar powder, glycerol, hot water, a saucepan, a stove, a spatula, and a candy thermometer. These ingredients should be readily available at your local grocery store. Remember, glycerol is also known as glycerine, so look for that if you can’t find glycerol. You will need the following amounts of each ingredient:

3g (½ tsp) glycerol

12g (4 tsp) gelatin or agar

60ml (¼ cup) hot water

Food coloring (optional)

Agar is a substance derived from algae that can be used in place of gelatin to make the bioplastic vegan friendly

2

Stir together all of the ingredients. Combine all of the ingredients in the saucepan and stir until there are no clumps left. You may need to use a whisk to disperse all of the clumps. Place the saucepan on the stove and start heating the mixture on medium-high heat.

If you want to color your plastic, you can add a few drops of food coloring at this step.

3

Heat the mixture to 95°C (203°F) or until it begins to froth. Put the candy thermometer into the mixture and monitor the temperature until it reaches approximately 95°C (203°F) or begins to froth. If the mixture begins to froth before it reaches temperature, that is okay. Remove it from the heat when it either reaches temperature or starts frothing.

Continue to stir the mixture while it is heating up.

4

Pour the plastic onto a smooth surface covered with foil or parchment paper. After you remove the pan from the heat source, you will need to remove any excessive froth. Spoon it out before pouring the plastic out of the pan. Stir everything to remove all clumps from the plastic.

If you just want to make plastic for fun, pour the mixture out onto a smooth surface. Make sure the surface is covered with foil or parchment paper so the plastic can be removed easily.

If you want to mold the plastic into a specific shape, you will need to do it during this step. Refer to the last method on molding for more details and help.

5

Leave the plastic to harden for at least two days. The amount of time it will take the plastic to harden is dependent upon how thick the piece is. Generally, it will take at least two days for it to fully dry out and harden. You can make this process go a little faster by using a blow dryer on the plastic. It’s easiest to leave the plastic undisturbed for a few days so it can dry on its own.

Once the plastic hardens, it can no longer be molded or shaped. If you want to shape it, you must do it while it is still warm and moldable.

Method3

Molding the Bioplastic

1

Make a mold for the plastic. A mold is the negative of a shape that you would like to make. You can make a cast of an object you would like to reproduce by sculpting two pieces of clay around the object. When the clay dries, remove the two pieces. If you fill each half with the liquid plastic and then put the halves together, you can make a copy of that object. You can also use a cookie cutter to cut shapes out of the plastic while it is still warm.

An alternative to making your own mold, is to purchase a mold at a craft or hobby shop.

2

Pour the hot plastic into the mold. Once you have a mold, you can use it to make more objects. While the plastic is still hot, pour it into the mold. Make sure that the plastic gets into the entire mold and try pop bubbles by lightly tapping the mold on the counter.

To make the object easier to remove when it dries, coat the mold with a non-stick spray before pouring the plastic in.

3

Let the plastic dry for at least two days. The plastic will take a few days to dry and fully harden. The amount of time it takes to dry is dependent upon the thickness of the object. If the object is very thick, it can take longer than two days to fully harden.

After two days, check the plastic. If it still appears to be wet, let it sit for another day and check it again. Continue to do this until the plastic is fully dry.

4

Remove your plastic from the mold. After waiting a few days, the plastic will be fully hardened and dry. At this point, you can remove the plastic from the mold. You have now made your own plastic version of whatever object you chose to mold.

You can reuse this mold to make as many plastic versions of the object as you like.

What role do glycerin and vinegar play in the manufacture of bio-plastics?

wikiHow Contributor

Community Answer

Glycerin is used as a plasticizer that links polymer chains together and allows them to slide past each other. Vinegar helps the corn starch to fully dissolve in the mixture because starch dissolves better in the presence of electrically charged ions. If you do not have vinegar handy, ordinary table salt can also be used to help the corn starch to dissolve because it can provide free ions.

The glycerine acts as a "plasticizer" to link polymer chains and allow them to bend. Sorbitol can also be used as a plasticizer in place of the glycerine. Glucose and sucrose can also be used as a plasticizer, although they are less common and you might need to do some experimenting on your own to get the amounts needed correct.

Depending on which country you reside in, corn flour and corn starch may be the same thing. Outside of the United States, many countries call corn starch corn flour. Within the United States, corn flour is similar enough to corn starch that it should work to make a homemade bioplastic.

The time it takes will vary based on the conditions for decomposition and the size of the plastic. Some bioplastics require high heat to decompose and cannot actually be composted in a back yard compost pile. It can take a few months to years for bioplastics to degrade.

How much time should I wait before I can mold the plastic into any shape?

wikiHow Contributor

Community Answer

The plastic should be molded immediately after heating. If you are molding it with your hands, you will want to let it cool enough that you can comfortably handle it. If you are pouring into a mold, simply pour it directly into the mold after removing it from the heat.

Video.

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Short Video: How to Make Bioplastic

The easiest way to make bioplastic is to combine 10mL of distilled water, 1 mL of white vinegar, 1.5 grams of cornstarch, and 0.5 grams of glycerol in a pot and stir. Boil the mixture until it becomes clear and thick, then pour it onto parchment paper in the shape you want. Let the mixture cool for 2 days or until fully hardened, then use! For help making bioplastic if you don’t have cornstarch, keep reading!

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Tips

These recipes can be altered by adding more glycerol for a rubbery finish, or less glycerol for a more rigid finish.

Article Info

This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article meets our high standards.